Hawking-Moss Tunneling with a Dirac-Born-Infeld Action

The Hawking-Moss tunneling rate for a field described by the Dirac-Born-Infeld action is calculated using a stochastic approach. We find that the effect of the non-trivial kinetic term is to enhance the tunneling rate, which can be exponentially significant. This result should be compared to the DBI enhancement found in the Coleman-de Luccia case.Comment: 4 pages, version accepted in Phys. Rev. D., additional references and example applicatio

A Brachistochrone Approach to Reconstruct the Inflaton Potential

We propose a new way to implement an inflationary prior to a cosmological dataset that incorporates the inflationary observables at arbitrary order. This approach employs an exponential form for the Hubble parameter $H(\phi)$ without taking the slow-roll approximation. At lowest non-trivial order, this $H(\phi)$ has the unique property that it is the solution to the brachistochrone problem for inflation.Comment: 13 pages, 2 figures, version matches published versio

A general and efficient representation of ancestral recombination graphs

As a result of recombination, adjacent nucleotides can have different paths of genetic inheritance and therefore the genealogical trees for a sample of DNA sequences vary along the genome. The structure capturing the details of these intricately interwoven paths of inheritance is referred to as an ancestral recombination graph (ARG). Classical formalisms have focused on mapping coalescence and recombination events to the nodes in an ARG. However, this approach is out of step with some modern developments, which do not represent genetic inheritance in terms of these events or explicitly infer them. We present a simple formalism that defines an ARG in terms of specific genomes and their intervals of genetic inheritance, and show how it generalizes these classical treatments and encompasses the outputs of recent methods. We discuss nuances arising from this more general structure, and argue that it forms an appropriate basis for a software standard in this rapidly growing field.</p

The Clinical Outcomes of Percutaneous Coronary Intervention Performed Without Pre-Procedural Aspirin

ObjectivesThe purpose of this study was to examine the incidence and outcomes of percutaneous coronary intervention (PCI) performed in patients who had not received pre-procedural aspirin.BackgroundAspirin is an essential component of peri-PCI pharmacotherapy. Previous studies suggest that pre-procedural aspirin is not administered to a clinically significant number of patients undergoing PCI.MethodsWe evaluated the incidence of PCIs performed without pre-procedural aspirin use among patients undergoing PCI from January 2010 through December 2011 at 44 hospitals in Michigan. Propensity-matched multivariate analysis was used to adjust for the nonrandom use of aspirin.ResultsOur study population comprised 65,175 patients, of whom 4,640 (7.1%) did not receive aspirin within 24 h before undergoing PCI. Aspirin nonreceivers were more likely to have had previous gastrointestinal bleeding or to present with cardiogenic shock or after cardiac arrest. In the propensity-matched analysis, absence of aspirin before PCI was associated with a higher rate of death (3.9% vs. 2.8%; odds ratio: 1.89 [95% confidence interval: 1.32 to 2.71], p < 0.001) and stroke (0.5% vs. 0.1%; odds ratio: 4.24 [95% confidence interval: 1.49 to 12.11], p = 0.007) with no difference in need for transfusions. This association was consistent across multiple pre-specified subgroups.ConclusionsA significant number of patients do not receive aspirin before undergoing PCI. Lack of aspirin before PCI was associated with significantly increased in-hospital mortality and stroke. Our study results support the need for quality efforts focused on optimizing aspirin use before PCI

Influence of calcium administration on the short-term hemodynamic and anti-ischemic effects of nifedipine

This prospective study investigated whether pretreatment with intravenously administered calcium would influence the effect of nifedipine on rest hemodynamics and treadmill performance in patients with ischemic heart disease. Seventeen patients were studied after undergoing a qualifying treadmill exercise test that revealed ST segment depression indicative of ischemic heart disease. Study subjects performed three additional treadmill tests as part of the protocol. One treadmill test was obtained from each patient to provide baseline measurements without a preceding intravenous infusion and in the absence of all antianginal drugs including nifedipine two additional exercise tests were preceded by an infusion and 10 mg of bite-and-swallow nifedipine. The infusions, administered in a randomized, double-blind, crossover fashion, consisted of either 10 ml of 10% calcium chloride (13.6 mEq) in 50 ml of 5% dextrose in water or 5% dextrose in water alone. Rest systolic blood pressure (134 +/- 4.6 mm Hg) was unchanged after placebo infusion (135 +/- 4.6 mm Hg) but decreased to 124 +/- 4.1 mm Hg (p less than 0.01) 25 min after nifedipine administration. Rest systolic blood pressure increased after calcium infusion (from 139 +/- 4.3 to 148 +/- 4.8 mm Hg, p less than 0.01) and then decreased significantly 25 min after nifedipine administration to 135 +/- 4.2 mm Hg (p less than 0.01). Despite a decrease at the time of peak nifedipine effect after either infusion, systolic blood pressure was significantly lower after administration of nifedipine alone than after administration of calcium and nifedipine (124 +/- 4.1 vs. 135 +/- 4.2 mm Hg, p less than 0.01)

The Epidemiology and Outcomes of Percutaneous Coronary Intervention Before High‐Risk Noncardiac Surgery in Contemporary Practice: Insights From the Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2) Registry

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139074/1/jah3534.pd